Even on a tight schedule, Odeon of Herodes Atticus Performance earns the hours.
Allow Evening (2–3 hours).
Seeing a performance under the stars in a 1,800-year-old marble theatre lit beneath the Acropolis is one of the most magical things you can do in Athens — bucket-list for the right night. The catch: it's only open for ticketed Athens Epidaurus Festival events (roughly June–Sept), the stone seats are punishingly hard (bring a cushion), and good shows sell out fast.